JUSTIN MCLEAN (BA (Hons) Sport Science (NWU))
RESEARCHING THE EFFECT OF VARIOUS COMPRESSION GEAR
ROCKETS, SKINS AND OTHER COMPRESSION GARMENTS – PHYSIOLOGICAL NECESSITY FOR ATHLETES
When one pictures any athlete, for example a triathlete, you will immediately visualize the image of James Cunnama crossing the finish line to take 1st place at Ironman 2010. He crossed the line wearing compression garments around his calf muscles and around his quadriceps muscles. Immediately athletes started to question whether these compression garments gave him an advantage above the other athletes. Well, let’s consider and take a look at some of the research that has been done on compression garments and sporting performance.
Compression garments can be considered as body-moulded, elastic suits that have an engineered compression gradient and can be worn as a full, lower, or upper-body piece (Duffield & Portus, 2007:409). Compression garments have been used for the past 50 years in medicine to reduce peripheral swelling and assist venous return in vascular patients (Duffield & Portus, 2007:409). According to Kemmler et al. (2009:101), some authors have found favorable effects of compression sleeves, tights and stockings on deep tissue oxygenation, arterial perfusion, venous hemodynamics, muscle oscillation, with corresponding effects on muscle soreness and lactate kinetics. These alterations should have a positive effect on overall performance and aerobic capacity (Kemmler et al, 2009:101).
It was only recently stated that commercially available compression garments will improve athletic performance (Duffield & Portus, 2007:410). It is still unknown whether such tights will compromise, or improve lower limb oxygenation (Bringard et al, 2006:549). There are currently several companies who sell garments, with little performance based evidence available to support the benefits of their use, or to compare between different brands for superior ergogenic benefits (Duffield & Portus, 2007:411):
It would therefore be essential for one to do research, so as to find scientific evidence that may substantiate these claims.
Possible benefits of compression garments:
It is extremely important for a researcher to consider the possible physiological benefits of wearing compression garments during competition, training and recovery periods. The question that will most certainly arise is whether these ‘possible physiological benefits’ will improve sport performance. Various experimental researchers have demonstrated the benefits of compression athletic wear towards comfort and physiological performances as follows (Liu & Little, 2009):
There have been many claims that athletic compression garment wear can increase the recovery rate of an athlete between training sessions and competitions. It is therefore necessary to refer to research that has been done on this particular topic, so as to support and find the truth behind these claims.
When one regards the case of sportsmen, it is now rather common to see them wearing elastic tights, or compression garments, especially during recovery periods after participating in strenuous physical activity inducing deleterious effects on muscular function (Bringard et al, 2006:549). According to Liu and Little (2009:51), SKINS claim that their compression garments reduce lactic acid build up immediately after periods of sustained exercise i.e. 37% after 2 hours and 15 minutes, and allows for a more rapid return to normal levels i.e. 38% in 20 minutes.
By making use of compression via garments in the 24 hour period following exercise, one may limit any swelling mechanisms that resulted from micro-trauma to the muscle (Duffield & Portus, 2007:411). According to Bringard (2006:548) the use of compression stockings is a well established therapy, which seems to have positive effects on leg swelling in patients. When compression stockings are worn, leg swelling will be significantly decreased after a day spent standing upright, or sitting down (Bringard et al, 2006:548).
Compression garments can also increase cardiac output by improving venous return, and so assist in recovery (Bringard et al, 2006:548). Bringard et al. (2006) found that compression garments counteract distal venous pooling and keep local tissue oxygenation constant.
All these factors in turn will allow for quicker and more effective recovery. Research has therefore supported these claims.
Explosive power/Anaerobic power:
There are many athletes and coaches who claim that compression garments may improve explosive power ability. The question to be asked is whether these claims can supported by scientific research?
The effects of lower body compression garments on exercise performance and power output in various sports has been examined by previous research (Sipes et al. 2011:8). According to Duffield and Portus (2007:411) there is currently no research on the effect of compression garments in improving the performance of exercise during intermittent, high-intensity activity, such as that observed during sports that involve repeated sprints.
Compression garments have become popularized by sports that involve power, for example volley ball, track and field and basketball (Kraemer et al, 1996:180). These types of sport are completely reliant on vertical jump ability (Kraemer et al, 1996:180). According to Kraemer et al. (1996:181) compression garments only showed to be beneficial for volley ball players in repetitive jump attempts and were not at all beneficial during maximal jump attempts.
According to Liu and Little (2009), no benefit for repeat-sprint, or throwing performance whilst wearing compression garments was found during their study. The influence of compression athletic wear on sprinting speed will therefore remain controversial (Liu & Little, 2009).
It is obvious from the above information that compression garments do not increase the explosive power ability of an athlete.
There are various endurance athletes out there in the sporting world who constantly make use of compression garments. These athletes include:
The question to ask is if it is beneficial for all of these athletes to wear compression garments during their various endurance orientated competitions?
According to Duffield and Portus (2007:409) compression garments that are worn during training and competition aid performance by improving venous return and peripheral circulation, reduce muscle osscilation, imrove clearance of blood lactate and improve clearance of markers of muscle damage, such as creatine kinase.
Although these changes should effect aerobic capacity positively, no study has shown healthy athletes with higher aerobic capacity and more favourable effects of compression garments have only been reported in a few studies (Kemmler, 2009:101).
According to Duffield and Portus (2007:412) maximal aerobic improvements with the use of compression garments have been reported in 5 minute maximum cycling efforts separated by an 80 minute recovery period.
Research therefore substantiates the claims that compression garments may increase the aerobic capacity of an athlete during competition and training.
Accordng to Liu and Little (2009:49), the dynamic interaction between the human body and compression athletic wear stimulates and triggers different receptors. Psychophysical properties deal with the relationships between physical stimuli and their subjective percepts, or correlates (Liu and Little, 2009:49). Liu and Little (2009:49) state that skin is very sensitive to mechanical stimuli. A skin displacement of less than 0.001mm can result in a sensation of pressure (Liu and Little, 2009:49). Liu and little (2209:45) found that a clothing pressure in the range of 30-45mmHg was found to produce a feeling of discomfort.
Psychopysical properties can therefore be regarded as an important consideration for optimizing user comfort of athletic wear and performance.
Maintenance of body core temperature during hot environmental conditions:
There are many sporting activities that require an athlete to participate outdoors in hot conditions. Examples could include the following:
According to Liu and Little (2009:50), radiant heat sources, high temperatures, high humidity and strenuous physical activity all have a potential for producing heat stress. Superior moisture and thermal regulation of athletic compression wear is therefore considered as an important approach in preventing heat stress and thus in achieving competitive performance (Liu and Little, 2009:50).
According to Liu and Little (2009:50), no difference was found in upper body sweat loss during exercise, when wool, or polyester garments were worn.
It is therefore obvious that further research needs to be done on this subject and we can therefore not conclude by saying that compression garments assist in maintaining core body temperature during hot environmental conditions.
Compression garment comfort:
We as athletes all know that we will not wear clothing that makes us feel uncomfortable, or that could affect our sporting performance. The question that should be asked is what are the major performance design considerations that one should think of whilst designing athletic compression garments for professional and recreational sportsmen and women?
According to Liu and Little (2009:51), the compression garment performance design considerations include the following:
The design of athletic compression garments therefore plays an important role in comfort and sporting performance.
This is one of the greatest questions asked when it comes to wearing compression garments during training and competition. Let’s consider the following research that could substantiate these claims.
According to Bernhardt and Anderson (2005:292) the use of compression shorts in rehabilitation and injury prevention has become very popular over the last decade with the commercialization of compression athletic wear. Light compression has been shown not to hinder performance, and garments that apply more compression have not yet been fully studied (Bernhardt & Anderson, 2005:292).
Subjective evaluations with regard to brace use are generally positive, with subjects feeling less pain and are therefore more confident (Bernhardt & Anderson, 2005:294). Less pain was experienced due to delayed onset of muscle soreness, and therefore performance was increased (Bernhardt & Anderson, 2005:294). In a study done by Bernhardt and Anderson (2005:94) subjective evaluations suggested that 93.31% of test subjects felt that compression shorts supported them.
According to Bernhardt and Anderson (2005:95) the use of compression shorts does not affect sporting performance and may be useful for injury prevention and during recovery from injury. This is mainly due to the fact that neural input is increased, as well as mechanical support (Bernhardt & Anderson, 2005:295).
It is therefore apparent that compression garments do play a role in injury prevention, as well as injury recovery.
Another question to be asked is whether compression garments can play a role in improving the proprioceptive ability of an athlete, and so increase the sporting performance of the athlete?
There is a steady increase in evidence stating that movement of skin overlying stretching muscle triggers cutaneous receptors and causes these receptors to send important joint position information to the brain (Bernhardt & Anderson, 2005:295). According to Bernhardt and Anderson (2005:295) skin stretch is an integral source of proprioceptive information.
If compression tends to enhance this effect, sensitivity will increase and thus support the use of bracing material around the joints of the body (Bernhardt & Anderson, 2005:295). The compressive quality of elastic braces is thought to make the stimuli of the underlying muscle tissue movement more prominent and in turn enhance cutaneous receptor activation (Bernhardt & Anderson, 2005:295).
It is therefore obvious that further research needs to be done on this subject and we cannot yet claim that athletic compression wear improves the proprioception of an athlete.
One can conclude from the above information that research has found that compression garments do have a positive influence on sport performance.
There appears to be a lot of positive results reported by athletes who make use of these compression garments, even though these reports might be of a subjective psychological nature.
A researcher can therefore not dismiss these claims, but accept the fact that further research is necessary to substantiate these claims.